| 摘要 |
PURPOSE:To obtain the title molding excellent in moisture absorption and release, water resistance, strengths, etc., by using a process comprising the step of molding a specified stock solution containing a PVA resin, a polymer having free carboxyl groups, etc., the step of stretching the molding under specified conditions, and the step of neutralizing the carboxyl groups. CONSTITUTION:This process comprises the step of molding a mixed aqueous solution, as a stock solution, containing a PVA resin (e.g. PVA) and a polymer having free carboxyl groups in the molecule (e.g. polyacrylic acid) in a weight ratio of 90:10 to 20:80 and a gelling agent (e.g. boric acid) for the resin, the step of stretching the molding at least unidirectionally at a stretch ratio of 2 or above when it is in the form of a line, and at least unidirectionally at an areal stretch ratio of 2 or above when it is in the form of a sheet, and the step of neutralizing the free carboxyl groups contained in the polymer of the obtained stretched molding. |
